Clinical impression suggests that adriamycin interferes with wound healing. Biomechanical and biochemical studies of wound healing in the rat have been undertaken. Thus far, we have shown that wound breaking strength is significantly reduced when adriamycin accompanies surgery up to three days post-op. Delaying administration of adriamycin by seven days post-op eliminates the deleterious effect. It appears that the defect contributing to reduced wound breaking strength in adriamycin-treated animals is not due to a collagen maturation defect but is due to a reduction in scar collagen accumulation as measured by "new" hydroxyproline content and reduced fiber diameter as determined by EM measurements. Previous reports intimated accelerated wound breaking strength by ultrasonic insonation. Four consecutive experiments with insonated and control groups of wounded rats failed to demonstrate this hypothesis.